This invention relates to electric capacitors or condensers and more particularly to wound capacitors which may be liquid-filled, encased units containing energy discharging means.
When a capacitor is disconnected from a source of power while it was charged, the energy stored in it can present an electrical shock hazard. Consequently, under some circumstances, it is desirable that a discharge resistance be connected across the electrodes of capacitors used in electrical equipment such as fluorescent lighting, high intensity discharge lighting, some appliances and other electrical apparatus. This requirement is for eliminating possible shock hazards from capacitors in such equipment to persons servicing or tampering with the apparatus.
In the past, discrete resistive components such as molded carbon composition resistors or similar parts have been assembled with and electrically connected across the external terminals of the capacitor. Discrete resistors have also been connected internally across the leads which connect the electrodes of encased capacitors to the terminals of the capacitor. This is both a bulky and costly arrangement for discharging such capacitors, in terms of the assembly and of the material utilized. Particularly, in small capacitors incorporating a discharge resistor inside the capacitor case, problems of design arise, related to heat dissipation and to the ability of the resistor to withstand the applied voltage.